When carrying out such operations it is essential to ensure a high degree of recovery (concentration) of the material being beneficiated, including materials containing large quantities of base minerals, such as pyrite, granite, magnetite. The same degree of recovery is essential during the treatment of initial materials containing high amounts of dust gold. Another requirement is to mechanize the processing stages and reduce labour intensity.
There are known rotary separators for beneficiating minerals, particularly gold (SU, A, 700,975 and 809,692) operating on the principle of concentrating base metals or minerals and comprising a base with a hub, a beneficiating member with a discharge hole, and a drive mechanism. The drive mechanism has the form of a hollow drive shaft journalled in bearings in the base hub and accommodating with an eccentricity in bearings a shaft of the beneficiating member travelling about a circle of a radius equal to the eccentricity. The beneficiating member is fashioned as a bowl having riffles at its inner surface.
However, the degree of concentration of metal, particularly gold, in this separator during beneficiating the initial material containing substantial amounts of gold and thin slices of gold is insuffucuent. For this reason, it is necessary to carry out repeated refining of the product, which makes the operation more labour- and time-consuming. Another disadvantage is the tendency of the bowl riffles to clog under the action of centrifugal forces when large amounts of heavy concentrates are present in the material, which negatively affects the beneficiation process.